The present invention relates to a changeable display unit for use in a sign device and more particularly, to a changeable display unit utilizing an electromagnet and a permanent magnet for selectively displaying desired images.
In many of the sign devices utilizing magnets known in the art, such as half-rotatable cylinder type sign devices or disc-type sign devices, such sign devices have to rotate 180.degree. so that the sign devices cannot display immediately desired images under the activation thereof. And there are spaces between a plurality of display units so that the marked images are not clear.